1. Field of the Invention
The present invention generally relates to the field of electronic flight instrument displays and, in particular, to primary flight displays, moving map displays, and engine parameter displays presented on electronic screens in aircraft cockpits.
2. Description of the Prior Art
It is well known in the art to provide displays presented on electronic screens in aircraft cockpits. Most modern commercial and military aircraft have several electronic screens capable of presenting: primary flight displays, moving maps or horizontal situation displays, engine parameter displays, and other displays. The present invention is directed to improvements and novel concepts related to primary flight displays, moving maps, and engine displays presented on electronic screens.
The primary flight display of the prior art consists of an electronic presentation of conventional flight data on a single screen. In other words, the symbology and information that would have been presented on separate airspeed indicators, altimeters, vertical speed indicators, artificial horizon/flight directors, and, in some cases, directional indicator/horizontal situation indicators, in pre-glass cockpit aircraft are presented together on a single display known as a primary flight display. Examples of prior art primary flight displays can be seen in U.S. Pat. Nos. 4,860,007, 5,136,301, 5,359,890, 5,412,382, and 5,844,504. All of the-prior art primary flight displays essentially involve recreating conventional two-dimensional flight symbology on electronic screens. They offer the advantage of compacting the pilot's instrument scan into a smaller area resulting in less fatigue. They also offer advanced warning capabilities and enhanced reliability over mechanical flight instruments. Nevertheless, despite the fact that electronic screens do not have the same physical limitations as mechanical instruments, current primary flight displays retain archaic two-dimensional symbology which does not impart information to the pilot in a natural manner. Thus, use of current primary flights displays still requires extensive training and practice and is subject to the same misinterpretation errors as mechanical instruments.
Flight path markers, also known as flight path vectors or velocity vectors, are commonplace on Heads Up Displays (HUD). As used on a HUD, flight path markers show the pilot the aircraft's projected flight path upon the outside world. Thus, flight path markers are extremely useful for directing an aircraft towards real world objects such as runways and targets. Examples of flight path markers used on HUDs can be seen at U.S. Pat. Nos. 4,454,496, 4,554,545, 5,357,263, 5,654,890, and 5,666,111. U.S. Pat. No. 5,296,854 shows a flight path marker used with a helmet mounted display rather than a HUD. Flight path markers have also been used on attitude display indicators and primary flight displays. An example of such a use can be found at U.S. Pat. No. 5,003,305. However, showing a flight path marker on such traditional two-dimensional displays greatly reduces the utility of the flight path marker, which is preferably used in conjunction with a three-dimensional background.
Current glass cockpit moving maps and horizontal situation indicators generally improve upon information presentation to the pilot significantly over older mechanical horizontal situation indicators and directional indicators. The current state of the art is embodied in moving maps such as Jeppessen Corporation's Flitemap, Archangel System's CDS, Avidyne Corporation's Navigator, and EFIS offerings from Rockwell, Honeywell and others. It is known, for example, to generate a moving map using navigational symbols whose parameters are stored in electronic memory. It is also known to integrate other types of data onto such moving maps to relay information to the pilot from a vertical perspective. Thus, in some embodiments prior art moving maps offer the capability of integrating lightning strike information, traffic information, radar information, data-link weather and traffic information, geographic information, and bit-mapped graphical chart information with the aforementioned navigational symbol database. However, current moving map systems only display information and do not further process information based upon altitude to show the pilot immediate threats to flight safety.
Finally, current engine parameter displays tend to replicate mechanical gauges complete with yellow and red arcs representing areas of adverse engine operation. Some engine parameter displays present their data in a bar format with markers showing areas of adverse engine operation. Some engine parameter displays also include digital readouts of the particular engine parameter. However, prior art engine parameter displays still require the pilot to compare the position of the analog pointers or pie wedges to the previously mentioned warning arcs or markers to ascertain out of limit conditions. In addition, prior art engine parameter displays, which display real time engine parameters, suffer from the same drawbacks as mechanical gauges when it comes to detection of trends.
Accordingly, there exists a need for novel electronic flight instrument displays that take full advantage of the power inherent in modern microprocessors to interact with the pilot in a natural manner and relieve the pilot from the demands of continuously monitoring, comparing, and making mental calculations. Thus, primary flight displays should incorporate a flight path marker and present the marker with three-dimensional backgrounds and symbology for optimal use. Moving maps should take account of aircraft altitude to select whether to display certain symbols and to determine the color (i.e. threat level) of those symbols that are displayed. Moving maps should also take account of an aircraft's attitude and flight dynamics to present the aircraft's projected path. Finally, engine displays should make it vividly apparent when a parameter is out of limits through use of color and should display certain critical engine parameters in a time-lapse manner to aid trend spotting. These needs are met by the present invention.